Which conformation of cyclohexane is chiral?

Among the following,the conformation that corresponds to the most stable conformation of meso-butane-$2,3$-diol is -

Least energetic conformation of cyclohexane is

In the following,the most stable conformation of $n-$butane is:

Explain the conformers of the Newman projection with an example.

Given below are two statements:
Statement $I$: There are several conformers for $n$-butane. Out of those conformers,the fully eclipsed conformer (dihedral angle $0^{\circ}$) is the least stable and the anti-staggered conformer (dihedral angle $180^{\circ}$) is the most stable.
Statement $II$: As the dihedral angle increases from $0^{\circ}$ to $60^{\circ}$,torsional strain decreases from the fully eclipsed conformer $(X)$ to the gauche conformer $(Y)$.
In the light of the above statements,choose the correct answer from the options given below: